Heat exchanger



2.1 is a top, front, and right side perspective view of a heat exchanger showing our new design;

2.2 is a top, front, and right side perspective view thereof, in which the right panel is removed and not shown;

2.3 is a right side perspective view thereof;

2.4 is a front perspective view thereof;

2.5 is a top perspective view thereof;

2.6 is an enlarged and partial top, front, and right side perspective view thereof; and

2.7 is a bottom, front, and right side perspective view thereof.

4.1 is a top, front, and right side perspective view of a heat exchanger showing our new design in accordance to a second embodiment;

4.2 is a right side perspective view thereof;

4.3 is a bottom, front, and right side perspective view thereof;

4.4 is an enlarged and partial top, front, and right side perspective view thereof;

4.5 is a top, front, and right side perspective view thereof, in which the right panel is removed and not shown; and

4.6 is a top perspective view thereof.

5.1 is a top, front, and right side perspective view of a heat exchanger showing our new design in accordance to a third embodiment;

5.2 is a right side perspective view thereof;

5.3 is a bottom, front, and right side perspective view thereof;

5.4 is an enlarged and partial top, front, and right side perspective view thereof;

5.5 is a top, front, and right side perspective view thereof, in which the right panel is removed and not shown; and

5.6 is a top perspective view thereof. 

CLAIM The ornamental design for a heat exchanger, as shown and described. 